I wouldn’t say it’s common, but it’s not exactly rare (to reasonably say “unique”) either. At the end of the day it’s just a form of operator overloading, and

I wouldn’t say it’s common, but it’s not exactly rare (to reasonably say “unique”) either. At the end of the day it’s just a form of operator overloading, and is generally present in languages that value expressiveness. Python and C++ (as mentioned), as well as Ruby, Rust, Kotlin from the top of my head. There are many more. By the way, slightly off-topic—Swift does have a fairly unique feature regarding operators: you can create entirely new ones, not just overloading those existing for some other types.